tslib is a runtime library for emitted TypeScript helper functions. It provides implementations for common tasks like class inheritance, iterator support, and asynchronous operations. By including tslib as a dependency, TypeScript projects can reduce code duplication and output smaller JavaScript bundles, especially when targeting older ECMAScript versions. This improves performance because these helper functions are heavily reused across compiled TypeScript code. Ensuring consistency and efficiency across different TypeScript versions and compilation targets.
tslib's release frequency is sporadic. Early versions (1.x) were released more frequently, with peaks in late 2016 and throughout 2017. Releases slowed significantly from 2019 to 2021. There was a resurgence in 2023 with versions 2.5 and 2.6, followed by a release of versions 2.7 and 2.8 in 2024. There have been no releases in the first seven months of 2025.
tslib downloads show a generally increasing trend from February 2024 to July 2025, peaking in June and July of 2025, surpassing 1.2 billion downloads. August 2025 shows a significant drop, but the month is incomplete.
